Gas turbines (GT) are often subjected to harsh operating conditions and prolonged operation times, leading to oxidation and corrosion wear of GT components. For GT compressor rotor blades, these factors cause surface finish degradation, adversely affecting the aerodynamic performance of the blades by increasing the coefficient of drag (CD) and resulting in reduced performance. Usually during major inspections, which are conducted at predetermined intervals, the rotor blades and stator vanes are manually scrubbed and/or cleaned to partially restore the surface finish of the blades and vanes. The scrubbing and/or cleaning of the rotor blades and vanes improves the surface finish, partially restoring GT output and efficiency. However, current methods of cleaning do not fully restore the surface finish to that of a new blade.
Manual scrubbing and/or cleaning of the rotor blades is a time-consuming process which results in a less than optimal surface finish of the blade. An alternative to manual scrubbing and/or cleaning of the rotor blades is electro-polishing of the rotor blades.
Electro-polishing of the rotor blades provides an improved surface finish of the blade, as compared to manual scrubbing. However, current electro-polishing practices require disassembly and/or transportation of the GT. Disassembly and transportation increase the GT downtime, resulting in lost productivity. Down time for transportation of the GT can be up to two months.
A refurbishing method that does not suffer from one or more of the above drawbacks is desirable in the art.